For a few days now, my fire 7, with CC installed, has been refusing to connect to One Drive.
Strangely, it always works, only a few days ago tells me that my user or psw are not right (which is absolutely not true, I tried to connect to One drive with the same account, and it works)

I've also tried to get my password sent, but he tells me that, at the moment there is a problem with the service...

I have also tried with Dropbox, but it remains to try to connect to infinity, and with Google Drive, but with this even does not give me access to the login
My CC is demo version.
I wanted to try it out before I bought the product....

don't waste your money
Most of the cloud functionality is broken now and the new developer is unresponsive. ( The original developers were very helpful but those days are gone )
The android app has not been updated since July 2018 and the iOS app was updated so badly that many customers libraries were destroyed.

You cannot connect a new install to dropbox unless you have a Gmail account and use the connect via Google option
I tried using google drive instead. But the app failed to find a good, complete copy of my calibre library when added to my Google drive

There is an alternative app called calibre box, but that only connects to cloud copies , not directly to a calibre content server.
Calibre go, another app in play store , has also been abandoned by its developer and does not connect to Dropbox. Even worse , it lies and tells you your library is corrupt when in fact your cloud library is fine, it's the app that is broken.

I can't comment on one drive connectivity except to say don't expect any help or support from the current developer. The android product is now abandon ware. I have now given up asking here when, if android issues will be fixed as all queries to date have been ignored.

A final workaround, if you use moon reader, is that moon can directly browse your Dropbox and get books from a calibre library in dropbox,. But you have to navigate first to the author sub folder and then to the book. If you don't happen to know how calibre has named the author subfolder then you are out of luck

However, I can not understand why, until a week ago, One Drive, worked well, without problems.
Sincerely the 'app, locally with the content server, is fine, I had found very good with the cloud, before it stopped working, but if it does not connect to any service ... not much use.

However, I can not understand why, until a week ago, One Drive, worked well, without problems.
Sincerely the 'app, locally with the content server, is fine, I had found very good with the cloud, before it stopped working, but if it does not connect to any service ... not much use.

Either there has been a change to one drive, by Microsoft, or you have changed the device that you are running the app on?
If you rule out the latter then I think it's a case of finding more info on one drive changes.

There is always the option of doing a forced stop, clear cache, restart app type of repair but if it is a Microsoft change then that will not help.

I don't use one drive myself, but can you test your access to it some other way e.g. from a different pc, to see if your credentials work?

Is there a way to get to one drive with the tablet browser, to test communication?

Or is there a one drive android app?
I know I can do that with Dropbox, Google drive, pcloud..but as I said, I am not a one drive user...

A final workaround, if you use moon reader, is that moon can directly browse your Dropbox and get books from a calibre library in dropbox,. But you have to navigate first to the author sub folder and then to the book. If you don't happen to know how calibre has named the author subfolder then you are out of luck

Moon+ Reader has OPDS support afaik. If you enable the Calibre content server, that's another option. It has a search function and supports browsing by custom columns.

One reason I never really got into CC is because my preferred reading apps all have OPDS support so short of being able to update Read status, there's really not much benefit that CC offers me. I actually find needing to switch between reader app and CC a pain.

@stumped - FYI, I use the Android Onedrive app directly most days of the week with no problems. The only time I had a problem was immediately after an Android upgrade, it was fixed within 24 hours by Google and/or MS.

I steer clear of using apps that rely on interoperating with multiple muddleware [sic] items from different suppliers.

I am not familiar with odps, but Google search took me to a project called calibre2odps which seems dead. And also gave me some old mobileread thread links, nothing newer than 2017.
So I remain unfamiliar with it.

if it's dead easy as ilovejedd suggests I will check it out in the morning when my library pc is back on. I just look for odps somewhere in moon and give it a content server IP address to try ?

You can't have too many connection options

The calibre content server with android cc still works, for most people, so providing the app is not removed from play store any time soon, that bit is ok. it's the cloud support that needs attention
I feel the need for making a backup apk coming on though, after typing that. As theres no guarantee that cc will stay in the store, for new device downloads. I note that an app called calibre cloud, or something similar , which i bought ages ago has now completely vanished and I never got around to backing that up.
Probably that calibre cloud guy, like the calibre-go guys , gave up when dropbox tweaked their api, and thus connects needed to be re coded.

It's built-in to the Calibre content server. Address to the feed would just have opds at the end:

http://<ip_address>:8080/opds

On Moon+, you go to Net Library >> tap on the 3 dots on upper right corner >> Add new catalog >> Calibre IP

That adds an entry named "calibre Library" at the bottom of the Net Library list.

thanks - i will try it later with Moon reader and report back as to how useful it looks
UPDATE
looks good, after fixing my typos, I am in. With lots of options: by newest/ title/author, series, rating, read...
so for me the string washttp://192.168.0.72:8080/opds

so that's now my fallback if CC disappears from play store completely

( i have a faint hope that the original owners will see the lack of support from the new owner, repossess it, and give the android app ownership to someone who is willing to engage with and respond to the user community ( those of use who are still here)

My wife connects quietly (to both Dropbox and One drive) with her Ipad (CC ios).
I keep getting the wrong username or password message...

I tried Calibre box, which works very well, with both services.
So I'm guessing the problem is really, and only, my CC .

I have solved it for a solution that includes Calibre Box for the cloud and Moon+ reader (that I already used) adding the Net Library (as recommended by Stumped), for the local content server of Calibre.
Thank you all for your advice and answers